Such fixing devices, which are particularly suitable for small-sized dispensers, are known in the state of the art. Thus, for example, document FR-2 719 292 discloses such a device for fixing a metering member in a receptacle containing the substance to be dispensed, in which the pump body is fixed directly in the neck of the receptacle by means of a ferrule which engages inside said pump body, the forced engagement of said ferrule in the pump body establishing a radial force which holds the pump body securely in the neck of the receptacle.
That device which is well adapted to certain dispensers, can turn out to be inadequate or ill-adapted to other types of dispenser.
Thus, in particular, when the same pump body needs to be fixed to receptacle necks of different diameters, the device of document FR-2 719 292 is unsuitable since the outside diameter of the pump body needs to correspond approximately to the inside diameter of the neck of the receptacle. Furthermore, although that device can accommodate manufacturing tolerances both in the neck of the receptacle and in the pump body, such accommodation is limited by the fact of the materials used for the receptacle body (generally glass) and for the pump body (generally a rigid plastics material).
Document FR-2 699 433 discloses an assembly device designed to be easy to assemble and disassemble in a manner similar to a tapering plug. That device has a rigid ring fixed to the pump body and one or more bushes of flexible material for fitting to necks of different diameters. Since the device needs to be easy to disassemble, it does not make it possible to achieve fixing that is reliable and that guarantees perfect sealing.